Wiskott-Aldrich syndrome protein (WASp) is a protein expressed in hematopoietic cells, the cells responsible for formation of blood components. WASp-family proteins are cytoskeletal proteins which are involved in actin polymerization, a process which is responsible for cell proliferation, motility, invasion and metastasis. WASp is a founding member of the Wiskott-Aldrich syndrome (WAS) family of proteins that share similar domain structure, and are involved in actin polymerization.
In addition to WASp, a human protein known as WASp interacting protein (WIP) is also expressed in hematopoietic cells. WIP binds to WASp and is involved in actin polymerization. Mutations or deletions in the Wiskott-Aldrich syndrome gene leading to lower levels of expression of properly functional WASp protein may lead to Wiskott-Aldrich syndrome (WAS). WAS is a rare hereditary disease, mainly prevalent in males, in which patients may suffer from a compromised immune system, eczema, autoimmunity and malignancies.
Another, less severe genetic disorder related to WASp and presenting similar symptoms to WAS is X-linked thrombocytopenia (XLT) characterized by low platelet counts, diarrhea and uncontrollable bleeding. Currently, treatments for WAS and XLT are focused on treating symptoms of the diseases rather than modifying WASp expression and function.